Issued a doctrinal letter to correct the writings of Patriarch Dionysius of Alexandria regarding the Trinity. The letter opposed Sabellianism, and insisted on the true doctrine of Three Persons in one Godhead. Sent large sums of money to the churches of Cappadocia for construction and the ransom of slaves; invading Goths had destroyed the buildings and enslaved the faithful. Brought order to the Church after a period of no leadership, and made peace with Emperor Gallienus who issued an edict of toleration. He condemned Paul of Samosata as a heretic. First pope to die not as a martyr.